A warehouse operator operating a public terminal warehouse located within the switching limits of St. Paul, Minneapolis, Duluth, or other terminal points under section 233.01, subdivision 3, shall annually publish a schedule of storage rates for the ensuing year. The schedule must be published during the first week in July in a newspaper published in the place where the warehouse is situated. The newspaper in which the rates are published must be a daily, if there is one. The rates may not be increased during the year and the warehouse operator may not discriminate in applying rates. The charges for receiving, handling, and delivering grain at a warehouse and the charges for storing grain in a warehouse must be fixed by the department, subject to Minnesota Statutes 1969, chapter 15.